1. Field of the Invention
The invention lies in the field of conveyor technology, and relates to a conveyor chain, which includes a plurality of chain links being connected to one another via pivoting bearings. The conveyor chain is particularly suitable for conveying individually held printed products, and for this purpose may include grippers, wherein for example one gripper is arranged on each chain link. The invention further relates to a method for the assembly of the chain links of the conveyor chain.
2. Description of Related Art
Conveyor paths with curves and twists in all directions can be realized with conveyor chains including chain links which are connected to one another via pivoting bearings or universal joints. Due to the pivoting bearings, adjacent chain links are pivotable in a limited manner relative to one another in all directions transverse to the chain length. The chains are usually guided in so-called chain channels, and the chain links include runner rollers on which they roll, on rails provided in the channels.
Each chain link of such a chain usually comprises two link plates which extend essentially in the chain longitudinal direction. The two link plates are connected to one another via a bolt at their one end (bolt end). A middle region of the bolt is mounted between the bolt ends of the link plates in a pivoting bearing being arranged at the other end (bearing end) of the link plates of an adjacent chain link. The two link plates of each chain link are, thus, connected to one another at their bolt ends via the bolt, and the pivoting bearing is arranged in the region of their bearing ends, wherein the bolt of each chain link is connected to the link plates of an adjacent link by being mounted in an articulated manner to the bearing ends of the link plates of this adjacent chain link.
Usually, a runner roller is arranged on both ends of the bolt of each chain link on the outer side of the link plates. A carrier body may be arranged between the bolt ends and the bearing ends of the link plates of each chain link, on which carrier body, for example, a gripper is mounted. The carrier body may additionally carry a third runner roller, whose axis is aligned perpendicularly to the bolt or to the axes of the other two runner rollers respectively.
Usually, a commercially available bearing bush is used as a pivoting bearing, and this bearing bush including a bearing housing forming a bearing cup, and a ball-like bearing body which is captured in the bearing cup and is freely rotatable therein. The bearing body has a cylindrical opening for receiving the bolt. The bearing housing is usually cylindrical and the bearing cup comprises two openings lying opposite one another, for the passage of the bolt. Usually, the bearing manufacturer produces the bearing housing as one piece, wherein the bearing cup is coated and closed around the bearing body. The bearing housing and the bearing body together form the bearing bush. For assembling the chain links, the bearing housing of the bush is connected to the bearing ends of the link plates of a chain link, and the bearing body of the bush is connected to the bolt of an adjacent chain link. Usually, an opening is provided at the bearing ends of the link plates for mounting the bearing housing, wherein these openings are matched to the outer diameter of the bearing housing. The two link plates are then fastened to one another, in a manner such that their bearing ends bear on one another, and that the two openings provided for the bearing housing are aligned to one another. The bearing bush is then positioned in the openings, and a connection between the bearing housing and the link plates is effected through calking, in a manner such that the bearing housing can neither be rotated nor moved in the axial direction relative to the link plates.